Fluid pressure brake apparatus



Feb. 21, 1950 K. H. LEECH ET AL FLUID PRESSURE BRAKE APPARATUS Filed Jan. 14, 1.947

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Patented Feb. 21, 1950 FLUID PRESSURE BRAKE APPARATUS K uai n. Leecli 1 1 Cherie: F. n. Shattock,

n n, Enslan gnors, 1 meme assigntalents, to The Westinghouse Air Brake Company, Wilmerding, Pa., a corporation of Penn- IYM Application January 14, 1947, Serial No. 722,058 In Great Britain February 22, 1946 (on. sot-1i 6 Claims.

This invention relates to fluid pressure brake apparatus and more particularly to structural improvements therein.

The usual fluid pressure brake systems employed in road and other vehiclescomprises. brake apparatus which necessarily exhausts fluid under pressure therefrom to the atmosphere during its operation. when this fluid pressure brake apparatus is used on public service vehicles. the noise createdby the exhaust therefrom is often objectionable to persons on or near the vehicle. 7 Such a fluid pressure brake apparatus as usually installed on a vehicle comprises devices which may require periodic attention and inspection and are therefore usually separately 2 3 indicates a control valve device for controlling supply of fluid under pressure from the reservoir I to a brake cylinder 4 or other device to be actuated by fluid under pressure and for controlling the release of said fluid therefrom, and 5 indicates a compressor unloader device.

The reservoir I may comprise a hollow cylindrical shell 6 to one end ofwhich is welded an end wall I and to the opposite end of which is welded an end wall 8, which may be concave. The shell I and walls I and 8 cooperate to define a reservoir chamber 9.

The tubular member 2 extends longitudinally through the reservoir chamber 9 and through mounted on the frame of the vehicle,'exposcd for the convenience of accessibility. These devices, operably connected by piping, are always subjected to a certain amount of vibration and shock during motion of the vehicle which may be sufllcient to break or otherwise cause fluid pressure leaks in the system and consequent operational failure of the brakes. These same devices so situated are often exposed to dust and dirt stirred up by motion of the vehicle which may gain entrance to vulnerable parts thereof, resulting in undue wear, damage, or failure of the equipment.

Therefore, one object of this invention is to provide a fluid pressure brake apparatus which is substantially free from objectionable exhaust noise as described above.

Another object of the invention is to provide a fluid pressure brake apparatus in which the working parts of devices thereof are protected ,from dust and dirt, while leaving parts which require periodical attention readily accessible.

Still another object of the invention is to provide a fluid pressure brake apparatus with a compact arrangement of devices which will result in economy of space as well as a reduction in the number of pipes required for said apparatus.

In the accompanying drawing; Fig. 1 is an end view of a fluid pressure brake apparatus embodying the invention; and Fig. 2 is a sectional view taken substantially along the line 2-2 on Fig. 1.

Description As shown in the drawing, the reference numeral I indicates a reservoir in which fluid under pressure supplied by a compressor (not shown), may be stored, 2 indicates a hollow tubular member which, according toone feature of the invention, is disposed within the reservoir I,

the end walls I and 8 to which the opposite ends of said member are respectively welded. An end member I0 is removably secured to one end of the tubular member 2 exteriorly of the reservoir I, which end member III comprises an integral hub portion II which has a central through bore I2 coaxial with the tubular member 2. An end cover portion I3 integrally formed with and pro.-

jecting radially out from the hub portion IL is curved toward the reservoir end wall 8 at its outer end and forms one wall of a curved annular passage II, oneend of which passage opens outside the reservoir I directed toward the outer face of the end wall 8, while the other end opens into the tubular member 2 by way of ports IS.

The control valve device 3 comprises a casing having integrally formed casin portions I6 and II at the junction of which is formed a flange it. The flange ll isbolted onto the end wall I,

disposing the casing portion I6 outside the reservoir I and the casing portion I! in the tubular member 2 within the reservoir. An annular shoulder I9 of the casing is disposed inside one end of the tubular member 2 for locating the casing portion I 1 which is symmetrical; coaxially within th member 2. The peripheral surface of the casing portionv II cooperates with the inner surface of the tubular member 2 to define an annular exhaust chamber 20 adjacent the shoulder Is at the innerend of portion I1 and a relatively narrow annular clearance exhaust passage .2l which extends from the annular exhaust chamber 20 to the outer end of the casing portion II to open into a relatively large volume exhaust chamber 22 in said tubular member,the

outer end of which chamber 22 is open to the atmosphere by way of ports I! and passage It in the end member II. The casing portion I8, as

viewed in the drawing. disposed outside one end of the reservoir I adjacent the bottom thereof,

lies substantially within transverse clearance disealing gasket 29 is disposed ina groove 36 in the flange l8 to surround the passage 28 for sealing cooperation with the outer face of the .end wall 1. A pipe and passage 3| communicates the chamber 24 in portion I6 with the brake cylinder 4. Supply and discharge control valves 32 and 33, respectively, are coaxially arranged and removably attached to opposite ends of a fluted valve stem 34 which is slidabiy mounted in the bore 26 in the partition 25.

The control valve 32 is disposed in the chamber 23 and is adapted by provision of a gasket 35 to seat on an annular seat rib 36 which is formed integral with the partition 25 to surround the bore 26 and project into the chamber 23. The valve 32 controls communication between chambers 23 and 24. A removable cap 31 is provided at the outer end of the casing in portion l6 out-' side the reservoir forming a wall of the chamber 23. The cap 31 allows for removal of the valve 32, the partition 25, and the valve 33. A spring 38 disposed in the chamber 23 bears against the cap 31 at its one end and the valve 32 at its opposite end to urge said valve to seat on the rib 36.

The control valve 33 is disposed in the chamber 24 and is adapted by provision of a gasket 39 to seal against one end of a sleeve 40 which is in slidable relationship with a bore 4|. I The sleeve 40 extends through the bore 4| and'projects into a larger bore 42 coaxial with the bore 4| and with the casing portion l1 in whichit is contained. An annular shoulder 43 is formed in the casing at the junction of the bores 4| and 42. A guide sleeve piston 44 is integrally attached to the projecting end of the sleeve 40 which piston is slidabiy mounted in the bore 42.- A bias spring 45 is disposed around the sleeve 49 in the bore 42 which spring is compressed by cooperation with the shoulder 43 at one end and at the opposite end by contact with the piston 44 to urge the attached sleeve 40 away from the control valve 33. A passage 46 is provided in the casing for communicating the chamber 24-with the bore 42 on th spring'side of the piston 44.

. Exhaust port or ports 41 are provided in the casing portion l1 which-open the outer end of the bore 42 to the annular chamber 20.

fLJA central bore 48 is provided in an enlarged portion of casing portion l1, the outer surface of fwhich portion defines the annular clearance exhaust passage 2| by cooperation with the inner taining rin 54, provided in the outer end of the bore-48, comprises an integral stop rib 55 which projects into the path of travel of the actuating member 50. One end of the ring 54 forms an annular stop shoulder 56 which projects into the path of travel of the annular ring 52. A

tween the annular rings 5| and 52 and bears against opposite faces thereof, urging said rings to separate. The ring 52 seats on the shoulder 56 of the retaining ring 54, while the ring 5| seats on the shoulder 49.

Two central bores 58 and 59 open into opposite ends of the cylindrical actuatin member 50, the inner ends ofwhich bores define a partition 68 in said member. One end of a control spring 6| projects through the bore 58 to bear against a respective face of the partition 68, while the opposite end bears against one face of the guide sleeve piston 44 to urge said piston and attachedsleeve 40 apart from the actuating member 50. One end of an operating rod 62 abuts against the opposite face of the partition 69, said operating rod being slidably mounted in the bore l2 and projecting through the chamber 22 in the tubular member 2 into the bore 59 in the actuating member 50. The operating rod 62 may be operable in any desired manner, as by a foot pedal (not shown).

The compressor unloader device 5 may be of the type which controls the supply of fluid under pressure from, a compressor to the reservoir in response to pressure of fluid contained therein; -With this type of control the compressor operates continuously, while the unloadin device 5 is arranged to load the compressor to cause fiuid under pressure to be supplied to the reservoir I when the demand-dictates and to unload the compressor by exhausting the discharge of fluid therefrom to the atmosphere when the demand drops off. 63 indicates a passage through which fluid is adapted to be exhausted to the atmosphere for unloading the compressor as just described. Unloaders of this general type are so well known that no further description thereof is essential in the present apparatus for an understanding of the invention.

The compressor unloader passage 63 opens into a port or passage 64 through the end wall 1. One end of a conduit 65 is welded to the inside face ofthe end wall 1 to enclose the port 64, while the opposite end is welded to the outer surface of the. tubular member 2 to surround a port 66 extending through said member, which port opens into the annular exhaust chamber 26.

Operation In operation, let it be assumed that the reservoir chamber 9 is charged with fluid under pressure and that the parts of the control valve device 3 are in the position as shown in Fig. 2, in which the control valve 32 is seated against the rib 36 by spring 38 so that fluid under pressure from chamber 9 is closed off from the chamber 24, and the sleeve 40 is withdrawn from the valve 33, opening the chamber 24 and the brake cylinder 4 to the atmosphere by way of the sleeve 49, the bore 42, the port or ports 41, the annular exhaust chamber 20, the clearance passage 2|, the chamber 22, and the ports l5 and passage M in the end member It].

To close off communication of the brake cylinexert a force on one end of the control spring 6| which in turn exerts a force on the guide sleeve piston 44 which overcomes the opposing action aeoaaoe of the relatively weaker bias spring 43 to move the 24 to the exhaust port or 41 by way orrth'e Further movement tion of a reservoir comprising a hollow cylindrical shell closed at one end by an end wall and closed at an opposite end by another end wall,

le a ti h d upnli'ialvefi J thexepmma acacia: thespring 33. The supply valve is thereby opened to allow the fluid under pressure supplied to the chamber 23 from the reservoir chamber 3 by way of the passage 2] and the port 23 to flow through the bore 23 into the chamber 24, hence through the passage and pipe 3| to the brake cylinder 4. As fluid under pressure thus flows through the chamber 24 to the brake cylinder 4, it also flows from said chamber through the passage 48 to the chamber at the left hand face of the piston 44 on which it acts against the opposing force of the spring SI, and when the pressure of said fluid is increased to a suflicient degree too'vercome said spring, said piston moves against said spring lit to allow the spring 33 to return the supply control valve 32 to lap with the rib 36 to close ofl supply of fluid under pressure to the brake cylinder 4. Movement of the operating rod toward the right reduces the pressure of the spring 3| on the piston 44 which allows the bias spring 45 to move the sleeve 43 out of contact with the gasket 39 on the discharge control valve 33 so that fluid under pressure from the brake cylinder 4 is exhausted through the chamber 24, the sleeve 43, the bore 42, the port or ports 41, the chamber 23, hence to the atmosphere as previously described.

Since the reservoir chamber 9 is charged with fluid under pressure let it be assumed that said pressure is sufficient to cause unloading of the compressor (not shown), then the compressor unloader device 5 will be exhausting the fluid discharged from said compressor, which operates continuously, through its exhaust port 33, into the port 64 in the end wall I, through the conduit 35 within the reservoir chamber 3', through the port 33 in the tubular member 2, into the chamber 23, whence it will flow to the atmosphere as above described. a

In flowing to the atmosphere, fluid from both the brake cylinder 4 and compressor unloader device 5 exhausts into the chamber 23, whence it passes through the relatively narrow passage 2| at the operating rod end of the control valve and expands into the relatively large volume chamber 22 of the remainder of the tubular member and finally escapes to the atmosphere through the end member I. at 'relativelylow velocity. Any sound from the exhaust of fluid thus discharged to the atmosphere is thereby muflled after leaving the chamber 23. The location of the tubular member 2 within the reservoir has an additional muiiling eflect on exhaust of fluid throughsaid member, and the inside face of the cover portion ii of the end member l3 serves to reflect sound waves back into the chamber 22 to prevent their transmission to the atmosphere, providing further muifling.

Having now described the invention, what is claimed to be new and is desired to be secured by Letters Patent is:

1. In fluid pressure apparatus, the combinaa tubular member extending longitudinally through said reservoir from said'one wall to said other wall and having therein a silencing chamber which is open to the atmosphere, a control valve device mounted on one of said end walls and projecting substantially into said tubular member, said device comprising a casing having an exhaust port which is open to said silencing chamber, a compressor umoader device mounted on said one end wall and having a fluid exhaust port, and means establishing communication between said exhaust port and said silencing chamber.

2. In fluid pressure apparatus, in combination, a reservoir for storing fluid under pressure, silencing means within said reservoir and open to the atmosphere, a compressor unloader device mounted'exteriorly on said reservoir, said device having a fluid exhaust port, and means within said reservoir establishing communication between said exhaust port and said silencing means.

3.' In fluid pressure apparatus, in combination, a reservoir comprising a cylindrical shell enclosed at each end by an end wall to form a chamber for storing fluid under pressure, a hollow member extending through said reservoir and sealed off from said chamber, a fluid pressure control device comprising a casing adapted to be mounted exteriorly of said reservoir on one end of said hollow member, said casing having a cored passage communicating said chamber with said fluid pressure control device, and an operating rod extending into the opposite end of said hollow member for actuating the control device.

4; In fluid pressure apparatus, in combination, a reservoir comprising a cylindrical shell enclosed at each end by an end wall to form a chamber for storing fluid under pressure, a hollow member extending through said reservoir sealed oil from said chamber, a fluid pressure control device comprising a casing mounted exteriorly of said reservoir on one of saidend walls and exe hollow member, said end member being provided with a central thru bore and an operating rod slidably disposed in and extending thru said bore into said hollow member for actuating said control means. a

5. In fluid pressure apparatus, a reservoir, a tube extending thru said reservoir and cooper-' ating therewith to form a fluid pressure storage chamber encircling said tube, a control valve device mounted on said reservoir over one end of said tube and comprising a casing portion extending into said one end of said tube, said portion cooperating with said tube to provide a relatively restricted annular passage connecting a fluid pressure exhaust cavity in said portion to a relatively large fluid pressure receiving volume in said tube at the end of said portion, and means closing the opposite end of said tube having an exhaust passage connecting said volume to atmosphere and so constructed as to direct exhaust fluid toward the outer surface of said reservoir.

6. In fluid pressure apparatus, a reservoir, 9.

tube extending thru said reservoir and cooperating therewith to form a fluid pressure storage tube and. comprising a portion extending into .said one end of said tube, said portion cooperating with said tube to provide a relatively restricted annular passage connecting a fluid pressure exhaust cavity in saidportion to a relatively large fluid pressure receiving volume in said tube,

at the end of said portion, means closing the opposite end 01' said tube having an axial bore and an exhaust passage connecting said volume to atmosphere, and an operating rod' for said 10 control valve extending thru said tube and axial KENNETH LEECH. CHARIES F. B. SHA'I'IOCK.

. f REFERENCES CITED .The foilowin'greferences are" of record flle of this patent:

2,239,549 Chipley Apr. 22, 1941 inthe 

